Izokibep Effective in 16 Weeks Among Patients with Moderate to Severe Hidradenitis Suppurativa

Early improvements with izokibep for hidradenitis suppurativa (HS) may be sustained or improved across disease measures through to Week 16, according to recent data.¹

These late-breaking findings were presented in a session at the European Academy of Dermatology and Venereology (EADV), with trial investigators including Kim A. Papp, MD, PhD, FRCPC, the founder and president of Probity Medical Research. Papp and colleagues had evaluated both the efficacy and the safety of izokibep, a novel interleukin (IL)-17A inhibitor, for patients living with moderate to severe HS.

The investigators highlighted HS as a chronic, systemic inflammatory skin condition marked by painful nodules, abscesses, and draining tunnels. Dysregulation of interleukin-17A (IL-17A) is said to be a key driver of the condition’s pathology. Izokibep, a novel molecule, has been engineered to selectively block IL-17A, given that it demonstrates exceptionally high binding affinity (Kd: 0.3 pM), has a small molecular size of 18.6 kDa—approximately 1-tenth that of a monoclonal antibody—and contains an albumin-binding domain designed to extend plasma half-life and potentially increase delivery to inflamed tissue.²

The 16-week results from a randomized, double-blind, placebo-controlled, multicentre, phase 3 study were highlighted by Papp and coauthors in these late-breaking findings. The phase 2b/3 trial involved the recruitment of individuals living with moderate to severe HS who had a confirmed diagnosis for at least 6 months and lesions in 2 or more anatomical areas. These areas would include at least 1 Hurley stage II or III area.

Participants in Papp and colleagues' research were required to have a lack of a total abscess and inflammatory nodule (AN) count of 5 or greater. They would also have to report a history of intolerance, inadequate response, or contraindication to oral antibiotics. Previous treatment with IL-17 or IL-17 receptor inhibitors was also not permitted.

Eligible individuals involved as study subjects were randomized to 1 of the following cohorts of the analysis: izokibep 160 mg once weekly (QW), placebo QW with crossover to izokibep 160 mg QW, or izokibep 160 mg QW (continued treatment)
Key efficacy measures that the investigative team assessed at Week 16 and which were sustained through Week 76 included HiSCR50/75/90/100 (attainment of ≥50%, 75%, 90%, or 100% reduction in participants' AN count). Additionally, any shifts in the Dermatology Life Quality Index (DLQI), skin pain improvements of ≥3 points on the Numeric Rating Scale (NRS), reductions in AN count to ≤2, and flare frequency. Safety evaluations included treatment-emergent adverse events (TEAEs), adverse events of special interest (AESIs), serious adverse events (SAEs), laboratory testing, and vital signs.

Izokibep was generally shown to be well tolerated, with Papp and colleagues concluded that no new safety concerns and no reported cases of candidiasis took place. Subjects being given izokibep experienced early and clinically meaningful improvements over placebo that were sustained through Week 16 and beyond.

More than one-third of treated subjects attained HiSCR75 at Week 16, and over 20% attained HiSCR100, suggesting complete clearance of AN lesions. Improvements were also observed in pain reduction, AN count, and quality of life scores, underscoring izokibep’s potential as a targeted therapy for moderate to severe HS.

References

1. Papp K, Bechara F, Kimball A, et al. Efficacy and safety of izokibep, a novel interleukin-17A inhibitor, in moderate to severe hidradenitis suppurativa: Week 16 results from a randomised, double-blind, placebo-controlled, multicentre, phase 3 study. Presented at the 2025 European Academy of Dermatology and Venereology (EADV) Congress, Sept 17-20, 2025.

2. Positive phase 3 results in hidradenitis suppurativa further strengthen competitive profile of izokibep. Affibody Medical AB. August 13, 2024. Accessed September 17, 2025. https://www.affibody.se/press/positive-phase-3-results-in-hidradenitis-suppurativa-further-strengthen-competitive-profile-of-izokibep/.